Jersey 2: Fix the root packages init parameter

The parameter name has changed from "com.sun.jersey.config.property.packages"
to "jersey.config.server.provider.packages". This parameter defines
the root packages that would be scanned for resources and providers.

The new name is also defined in the constant ServerProperties.PROVIDER_PACKAGES.

Reference: https://eclipse-ee4j.github.io/jersey.github.io/apidocs/2.37/jersey/org/glassfish/jersey/server/ServerProperties.html#PROVIDER_PACKAGES
diff --git a/core/src/main/java/de/ids_mannheim/korap/server/KustvaktBaseServer.java b/core/src/main/java/de/ids_mannheim/korap/server/KustvaktBaseServer.java
index a97873b..a5d6bca 100644
--- a/core/src/main/java/de/ids_mannheim/korap/server/KustvaktBaseServer.java
+++ b/core/src/main/java/de/ids_mannheim/korap/server/KustvaktBaseServer.java
@@ -22,6 +22,7 @@
 import org.eclipse.jetty.servlet.ServletHolder;
 import org.springframework.web.context.ContextLoaderListener;
 
+import org.glassfish.jersey.server.ServerProperties;
 import org.glassfish.jersey.servlet.ServletContainer;
 
 import de.ids_mannheim.korap.config.KustvaktConfiguration;
@@ -111,7 +112,7 @@
 
         ServletHolder servletHolder = new ServletHolder(new ServletContainer());
         servletHolder.setInitParameter(
-                "com.sun.jersey.config.property.packages", rootPackages);
+                ServerProperties.PROVIDER_PACKAGES, rootPackages);
         servletHolder.setInitOrder(1);
         contextHandler.addServlet(servletHolder, config.getBaseURL());